LEINSTER's season continues its curious trajectory, punch-drunk but still clinging to their place at the top table as Ireland's sole representative.

As Matt O'Connor pointed out, they are 160 minutes away from being crowned Europe's best team and are confirmed as one of the top four this season, but they remain a frustratingly inhibited team under the Australian, whose over-riding emotion in the aftermath was relief.

Under the circumstances, the result was all that really mattered at the Aviva Stadium for the three-time champions, whose core team had not played together in blue since January.

O'Connor was counting on his Ireland stars bringing their Six Nations form to the premier club competition and, by and large, they did just that.

Destroyed

With six Ireland international front-rows in the match-day 23, the Leinster pack destroyed Bath in the scrum - 12 of Ian Madigan's 18 points came as a result of penalties from the set-piece.

That they had to rely on the boot of their inside-centre for the third time in seven European games this season told a different story, however, one of a team who remain short on cutting edge despite having plenty of talent in the outside channels.

"I wouldn't be too worried about the performance, it was about the result. It doesn't make a difference how much you win by in knockout rugby," the coach argued, before conceding they won't be able to depend entirely on Madigan in the semi-final.

"You've probably got to score tries against Toulon to win, I don't think we'll have the same dominance at set-piece as we had today.

"But you can only play the dynamics, if they're going to infringe and it makes it very, very hard to get that speed of release and that opportunity to put them to the sword. We did some good things with the ball, there was a couple of genuine try-scoring opportunities that we didn't take.

"When you're getting penalties at scrum, it probably nullifies your ability to play from those exchanges which we would back ourselves to outplay most sides from scrums. There was a dynamic at play that we knew and planned for and it's probably going to be a different dynamic in Toulon."

O'Connor could have been reflecting on a much more comfortable afternoon had his side been more ruthless in the spell shortly after half-time when they threatened to put the game to bed.

Having build a 15-5 half-time lead and with Jerome Garces playing advantage, they put together their best attacking phases of the game but Zane Kirchner was bundled into touch by a brilliant Micky Young tackle.

Then Rob Kearney's long-range drop-goal attempt sailed just wide. Seconds later, the full-back kicked the ball straight into touch from his own 22, Bath scored from the lineout thanks to their brilliant fly-half George Ford, and the last half-an-hour would take on an unnecessarily stressful hue.

In the end, it was Leinster's discipline that won them the game. They conceded just four penalties to Bath's 12 and when Garces was faced with a 50-50 call on the last play, he favoured the team who had got on his right side.

That Leinster ended up defending their '22' on the last play of a three-point game will dominate their review, as will the number of missed tackles that allowed Bath look so good.

Madigan's accuracy off the tee punished the visitors who were guilty of undoing plenty of fine work with ball in hand thanks to Ford's ability to identify space and Anthony Watson's brilliant counter-attacking play.

The Leinster centre opened the scoring, but was then guilty of a terrible missed tackle on Horacio Agulla that allowed Bath field position from which Ford stepped outside Devin Toner's reach to score a fine individual try.

He missed the conversion and Toner atoned by claiming the restart. The rest of the half saw Leinster dominate possession, territory and set-piece and build a score with Watson in the sin-bin for taking Kearney out in the air.

They finished the half 15-5 up and with a dominant defensive last play that seemed to emphasise their dominance, but they went for the jugular and missed, which allowed Bath counter-punch their way back with Ford scything through a gap between Cian Healy and Ford to set up his captain Stuart Hooper to score.

Responded

Madigan responded with a penalty after Marty Moore had taken over where Mike Ross left off and forced Paul James into collapsing, but Leinster stopped playing from there.

With Jamie Heaslip later describing the game as as quick as any international he's played in, their decision to kick for territory failed to take a tired chasing game into account and Bath caused them all sorts of problems on the counter.

Ford narrowed the gap to three after Sean O'Brien came in from the side, but a combination of Bath inaccuracy and Leinster's defence kept them at bay.

Ultimately, it came down to one last ruck as the clock went red. Richardt Strauss played the ball on the deck as Matt Garvey cleared him out from the side. Both were illegal, Garces' arm went up and the Aviva Stadium sighed in unison. Leinster were in the last four.

"We're 160 minutes away," O'Connor said when asked to assess his side's chances of a fourth title in seven years.

"The margins are tiny, against really good sides at this level you've got to be really good across the course of it. We let ourselves down off the back of a great start, not to put them to the sword, and I don't think you'll get away with that in Toulon."